Biodiversity Data Journal 7: e32625 doi: 10.3897/BDJ.7.e32625 Data Paper Standardised inventories of spiders (Arachnida, Araneae) of Macaronesia I: The native forests of the Azores (Pico and Terceira islands) Jagoba Malumbres-Olarte‡,§, Pedro Cardoso §,|,‡, Luís Carlos Fonseca Crespo¶,§, Rosalina Gabriel‡, Fernando Pereira‡‡, Rui Carvalho , Carla Rego‡‡, Rui Nunes , Maria Teresa Ferreira‡, Isabel R. Amorim‡, François Rigal #,‡, Paulo A. V. Borges‡,¤ ‡ cE3c – Centre for Ecology, Evolution and Environmental Changes / Azorean Biodiversity Group and Universidade dos Açores, Rua Capitão João d’Ávila, São Pedro, 9700-042 , Angra do Heroísmo, Azores, Portugal § LIBRe – Laboratory for Integrative Biodiversity Research, Finnish Museum of Natural History, University of Helsinki, Helsinki, Finland | IUCN SSC Spider & Scorpion Specialist Group, Helsinki, Finland ¶ Biodiversity Research Institute UB, Department of Evolutionary Biology, Ecology and Environmental Sciences (Athropods), Av. Diagonal 645, E-08028, Barcelona, Spain # CNRS/ L'Université de Pau et des Pays de l’Adour/ E2S UPPA, Institut Des Sciences Analytiques et de Physico – Chimie pour L'environnement et les Materiaux – MIRA*, UMR5254, 64000, Pau, France ¤ IUCN SSC Mid-Atlantic Islands Specialist Group, Angra do Heroísmo, Azores, Portugal Corresponding author: Jagoba Malumbres-Olarte ([email protected]) Academic editor: Jeremy Miller Received: 26 Dec 2018 | Accepted: 08 Mar 2019 | Published: 16 Apr 2019 Citation: Malumbres-Olarte J, Cardoso P, Crespo L, Gabriel R, Pereira F, Carvalho R, Rego C, Nunes R, Ferreira M, Amorim I, Rigal F, Borges P (2019) Standardised inventories of spiders (Arachnida, Araneae) of Macaronesia I: The native forests of the Azores (Pico and Terceira islands). Biodiversity Data Journal 7: e32625. https://doi.org/10.3897/BDJ.7.e32625 Abstract Background The data presented here come from samples collected as part of two recent research projects (NETBIOME - ISLANDBIODIV and FCT - MACDIV) which aimed at understanding the drivers of community assembly in Macaronesian islands. We applied the sampling protocol COBRA (Conservation Oriented Biodiversity Rapid Assessment, Cardoso 2009) in sixteen 50 m x 50 m native forest plots in the Azorean Islands of Pico (6 plots) and Terceira © Malumbres-Olarte J et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. 2 Malumbres-Olarte J et al (10 plots) to assess spider diversity. Through this publication, we contribute to the knowledge of the arachnofauna of the Azores and, more specifically, to that of the islands of Pico and Terceira. New information The collected samples yielded 8,789 specimens, of which 45% were adults (3,970) belonging to 13 families, 36 species and three morphospecies that have yet to be described. Species of the family Linyphiidae dominated the samples, with 17 species and two morphospecies that have yet to be described (48% of the taxa). Out of the identified (morpho)species, 16 were introduced, 13 Azorean endemic (three of which were undescribed) and seven native (five of them Macaronesian endemics). We report the first record of the introduced species Haplodrassus signifer and Agyneta decora in Pico Island. Keywords Arthropoda, Araneae, Azores, Terceira, Pico, native forest, exotic species, standardised sampling Introduction Despite six centuries of disturbance and land use changes, the Azorean islands still contain areas covered by unique native forest (Triantis et al. 2010). This forest accounts for about 5% of the total area of the archipelago and is mainly present on the islands of Flores, Pico and Terceira (Gaspar et al. 2010). From a conservation perspective, the importance of these forests resides in their being home to numerous endemic arthropod species, many of which have been given different status of conservation concern following the IUCN Red List criteria (see for the insects Borges et al. 2017, Borges et al. 2018a). Furthermore, many species – mainly arthropods – await discovery and taxonomic description, despite the high rate of taxonomic descriptions in the last decades (Lobo and Borges 2010). For instance, 24 out of the known 26 endemic spiders have been described since 1989 (Borges and Wunderlich 2008, Borges et al. 2010, Crespo et al. 2013, Crespo et al. 2014). Indeed, the effective, appropriate and efficient conservation of ecologically valuable areas requires knowing the identity and colonisation status of species (i.e. endemic, native non- endemic or introduced), often provided by large-scale projects such as the EU NETBIOME funded ISLANDBIODIV (Understanding biodiversity dynamics in tropical and subtropical islands in an aid to science based conservation action) and the Portuguese FCT funded MACDIV (Macaronesian Islands as a testing ground to assess biodiversity drivers at multiple scales). Both ISLANDBIODIV and MACDIV aim to unveil the diversity patterns in vascular plants, springtails, beetles and spiders at local and regional scales in Macaronesian islands (see Emerson et al. 2016, Cicconardi et al. 2017, Borges et al. Standardised inventories of spiders (Arachnida, Araneae) of Macaronesia ... 3 2018b). Here we present the information on the species collected in the Azorean forest plots that are part of the ISLANDBIODIV and MACDIV projects. Sampling methods Study extent: On each of the Azorean islands of Pico and Terceira, we established six and ten 50 m x 50 m plots along a longitudinal distance of 20 km and 13 km, respectively. In Pico, each plot is located at increasing distances from a first, reference plot (Table 1): 0.1, 1, 5, 10 and 20 km (Fig. 1), covering the three existing forest fragments in order to test distance decay patterns on beta diversity in a log scale within project MACDIV. In Terceira, the 10 plots were randomly distributed in the four main fragments of native forest also to test patterns of alpha and beta diversity (see Cicconardi et al. 2017, Borges et al. 2018b). All plots were located in mid to high elevation native forest dominated by Juniperus brevifolia, Laurus azorica and Ilex perado subsp. azorica trees (see Borges et al. 2018b for more details on the surveyed habitats) (Fig. 2). Table 1. Coordinates of sampling plots. Plot Longitude Latitude Pico 1 -28.2017136846 38.437588 Pico 2 -28.2117989478 38.437737 Pico 3 -28.2259599451 38.434491 Pico 4 -28.257662125 38.4561062785 Pico 5 -28.2733451278 38.4876669302 Pico 6 -28.4228543692 38.4998686917 Terceira 1 -27.1971972222 38.7320583333 Terceira 2 -27.2005772537 38.7364977463 Terceira 3 -27.2271119278 38.7334147054 Terceira 4 -27.2193222222 38.7617777778 Terceira 5 -27.3074033132 38.7355657746 Terceira 6 -27.3313027778 38.7520777778 Terceira 7 -27.233098 38.75214 4 Malumbres-Olarte J et al Terceira 8 -27.3198583333 38.7471444444 Terceira 9 -27.2899410553 38.7372469297 Terceira 10 -27.2072466047 38.7501938461 Figure 1. Figure 1. Location of plots in Pico (left) and Terceira (right) islands. Figure 2. The native forest of Azores: Terra-Brava at Terceira Island - Plot Terceira 1 (Credit: Paulo A. V. Borges). Sampling description: We sampled all plots using the optimised and standardised COBRA (Conservation Oriented Biodiversity Rapid Assessment) protocol for temperate forests (Cardoso 2009). Different variants of the COBRA protocol for spiders and beetles have Standardised inventories of spiders (Arachnida, Araneae) of Macaronesia ... 5 already been applied in oceanic islands (Emerson et al. 2016) and for spiders on tropical forests (Malumbres-Olarte et al. 2016, Malumbres-Olarte et al. 2018). Although originally developed and optimised for mainland temperate and Mediterranean habitats, COBRA protocols have been recently proposed as the standard protocols for inventorying and monitoring spiders and beetles in island forest ecosystems (Borges et al. 2018c). The COBRA protocol, when applied to temperate forests, consists of: four night aerial samples (1 hour / sample), two day sweeping samples and two night sweeping samples (1 hour / sample), two day beating samples and two night beating samples (1 hour / sample) and 12 pitfall samples (4 traps / sample). Specifically for islands, we added two sampling methodologies to also cover beetle diversity (Borges et al. 2018c): two diurnal active aerial searching under bark, lichens and bryophytes (ABS) (1 hour / sample) and two diurnal active aerial searching in decaying trunks, dead wood on the ground and under stones (GWS) (1 hour / sample). We collected all samples in July 2016 (Pico, MACDIV) and in June-September 2012 (Terceira, ISLANDBIODIV). Geographic coverage Description: Pico and Terceira Islands, the Azores, Macaronesia, Portugal Coordinates: 38.434491 and 38.7617777778 Latitude; -28.4228543692 and -27.1971972222 Longitude. Taxonomic coverage Taxa included: Rank Scientific Name Common Name order Araneae Spiders Temporal coverage Single date: 2012-6-01; 2016-9-26. Collection data Collection name: Dalberto Teixeira Pombo insect collection at the University of Azores Collection identifier: DTP Specimen preservation method: All specimens were preserved in 96% ethanol Curatorial unit: Dalberto Teixeira Pombo insect collection at the University of Azores (Curator: Paulo A. V. Borges) 6 Malumbres-Olarte J et al Usage rights Use license: Open Data Commons Attribution License IP rights notes: CC-BY 4.0 Data resources Data package title: MACDIV_COBRA_Azores_Forest